Tetracycline Hydrochloride Ophthalmic Ointment

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

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1 DEFINITION

Tetracycline Hydrochloride Ophthalmic Ointment contains NLT 90.0% and NMT 125.0% of the labeled amount of tetracycline hydrochloride (C₂₂H₂₄N₂O₈ · HCl).

2 IDENTIFICATION

A. The retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.

3 ASSAY

PROCEDURE

Solution A: 0.1 M ammonium oxalate

Solution B: 0.2 M dibasic ammonium phosphate Diluent: Dimethylformamide and Solution A (270:680)

Mobile phase: Dimethylformamide, Solution A, and Solution B (270:680:50). Adjust, if necessary, with 3 N ammonium hy droxide or 3 N phosphoric acid to a pH of 7.6–7.7.

System suitability solution: 100 µg/mL of tetracycline hydrochloride and 25 µg/mL of USP 4-Epianhy drotetracy cline Hy drochloride RS in Diluent

Standard stock solution: 1 mg/mL of USP Tetracycline Hydrochloride RS in methanol

Standard solution: 0.12 mg/mL of USP Tetracy cline Hy drochloride RS from Standard stock solution in Diluent

Sample stock solution: Nominally 3 mg/mL of tetracycline hydrochloride prepared as follows. Transfer a portion of Ophthalmic Ointment, containing nominally 300 mg of tetracycline hydrochloride, to a glass-stoppered conical flask. Add 20 mL of cy clohexane, and shake. Add 35 mL of methanol, and sonicate for 20 min. Filter this solution into a 100-mL volumetric flask, and rinse the sides of the conical flask with 40 mL of methanol, filtering the rinsing into the volumetric flask. Dilute with methanol to volume.

Sample solution: Nominally 0.12 mg/mL of tetracycline hydrochloride in Diluent from Sample stock solution

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 280 nm

Columns

Guard: 4.6-mm × 3-cm; 10-µm packing L7

Analytical: 4.6-mm × 25-cm; 5–10-µm packing L7

Flow rate: 2 mL/min

Injection volume: 20 µL

System suitability

Samples: System suitability solution and Standard solution

[NOTE—The relative retention times of 4-epianhydrotetracycline and tetracycline are 0.9 and 1.0, respectively.]

Suitability requirements

Resolution: NLT 1.2 between 4-epianhydrotetracycline and tetracycline, System suitability solution

Relative standard deviation: NMT 2.0%, Standard solution

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of tetracycline hydrochloride (C₂₂H₂₄N₂O₈ · HCl) in the portion of Ophthalmic Ointment taken:

Result = (r_U/r_S) × (C_S/C_U) × P × F × 100

r_U = peak response of tetracycline from the Sample solution

r_S = peak response of tetracycline from the Standard solution

C_S = concentration of USP Tetracycline Hydrochloride RS in the Standard solution (mg/mL)

C_U = nominal concentration of tetracycline hydrochloride in the Sample solution (mg/mL)

P = potency of USP Tetracycline Hydrochloride RS (µg/mg)

F = conversion factor, 0.001 mg/µg

Acceptance criteria: 90.0%–125.0%

4 SPECIFIC TESTS

STERILITY TESTS 〈71〉: Meets the requirements

OTHER REQUIREMENTS: It meets the requirements for Particulate and Foreign Matter and Container Contents in Ophthalmic Products—Quality Tests 〈771〉, Drug Product Quality, Universal Tests, Particulate and Foreign Matter and Container Contents.

5 ADDITIONAL REQUIREMENTS

PACKAGING AND STORAGE: Preserve in collapsible ophthalmic ointment tubes.

USP REFERENCE STANDARDS 〈11〉

USP 4-Epianhydrotetracycline Hydrochloride RS    C₂₂H₂₄N₂O₇ · HCl    462.88

USP Tetracycline Hydrochloride RS